Single lens reflex digital cameras have rapidly grown in popularity in recent years. With these single lens reflex digital cameras, when a subject is observed through an optical viewfinder, the light incident on the imaging optical system is reflected by a reflecting mirror disposed along the optical path, and is guided to the viewfinder optical system. As a result, the subject image is converted by a pentaprism or the like into an erect image and guided to the viewfinder optical system. This allows the user to view the subject image formed by the imaging optical system through the optical viewfinder. Thus, the reflecting mirror is usually disposed along the optical path.
Meanwhile, when an optical image of the subject is converted into an image signal, the reflecting mirror is retracted from the optical path so that the light from the imaging optical system will be incident on an imaging element. As a result, opto-electric conversion is performed by the imaging element, and image data about the subject is obtained. When imaging is complete, the reflecting mirror is returned to its home position along the optical path. With a single-lens reflex camera, this operation of the reflecting mirror is the same regardless of whether the camera is a conventional silver halide camera or a digital camera.
However, when the home position of the reflecting mirror lies in the optical path, the light from the imaging optical system is not incident on the imaging element. Therefore, in the case of a digital camera, a monitor photography mode, in which the user uses a liquid crystal monitor to view the subject, is not possible, and a camera system such as this is inconvenient for a beginner unaccustomed to photography.
In view of this, a single-lens reflex digital camera has been proposed with which a liquid crystal monitor can be used during image capture (see Patent Citation 1, for example). With this camera system, in monitor photography mode, the reflecting mirror is retracted from the optical path and the light from the imaging optical system is incident on the imaging element. This allows the subject to be viewed on the liquid crystal monitor.
Patent Citation 1: Japanese Laid-Open Patent Application 2001-125173